Multi-time scale coordinated scheduling for the combined system of wind power, photovoltaic, thermal generator, hydro pumped storage and batteries

Grid connection of random renewable energy such as wind power and photovoltaic results in difficulties of keeping power balance for power system operation. In order to solve this problem, this paper proposed a multi-time scale coordinated scheduling model for the combined system of Wind power-Photovoltaic-Thermal generator-Hydro pumped storage-Battery (WPTHB) by taking advantages of their complementary operation characteristics. The scheduling model is composed of three time scales: the day-ahead scheduling, the 1-hour ahead scheduling and 15-minute ahead scheduling. 1) in the day-ahead scheduling, based on the day-ahead forecast data of Wind-Photovoltaic power and Load demand (WPL), the optimal power outputs of thermal power units in 24 hours are solved from a mix integer linear programing (MILP) model to achieve the minimal operation cost of thermal units. 2) In the 1-hour ahead scheduling, based on power outputs of thermal units solved in the day-ahead scheduling and the 1-hour-ahead forecasted WPL, the hydro pumped storage power output is optimized to achieve its minimal operation cost. 3) In the 15-minute ahead scheduling, based on the day-ahead optimal power outputs of thermal units and the 1-hour ahead optimal outputs of pumped storages, the battery optimal power generation is obtained from a AC optimal power flow model solved by MATPOWER. Simulations of New England system validate that the proposed multi-time scale coordinated scheduling model could fully explore the different power regulation speeds and capacity of hydro pumped storages, thermal power generators and batteries to effectively alleviate WPL variations and achieve economic operation for multi-source generation systems.